Just finished my basement. Let me share some lessons’ learned. Do not nail to existing floor joist. They have bowed and warped over the years, which will throw your level/plum off. I used metal studs. if you have concerns with water. If not, pressure treated is recommended for the bottom plate/nailer. Also watch for floor joist flexing.
Good Luck.. Don't forget to upgrade your electrical outlet count in the basement too

I'm reading this and I don't know what everyone is going for. I've been doing basement builds for years and the easiest way to build walls is to build them on the floor and stand them up to the existing floor joists. Measure all along where the wall is going and build it about 3/4" short of the shortest measurement. Within reason of course, if the concrete is off more than an inch cut the studs in accordance. Shoot it into the floor, level and plumb it out, shim to floor joists and screw it into them.

Metal studs are easy to work with but can be a pain in a residential setting, hanging pictures, sound transfer, and not as strong if only one side drywalled. And the bottom track will rust if there is ANY moisture in the concrete. (To check for moisture duct tape a 2' X 2' piece of poly to the floor and check it for moisture in 2 days.) If you do find moisture you can still use metal, but put down a wood 2X4 and build the wall on top of that.

Another hint...leave about an inch or so between the basement walls and new wall. Makes it SO much easier when you run the electric!!